便血合并皮肤黄染、蜘蛛痣及肝掌，首先考虑（）。
A.结肠癌
B.胃底食管静脉破裂出血
C.消化性溃疡
D.急性胆囊炎
E.胃癌
参考答案：B
已知函数f（x）的图象关于原点对称，且当x＜0时，f（x）=2x-4，那么当x＞0时，f（x）=______．
How is the weather like().
A.Good enough for outing.
B.Bad.
C.Not as good as it was a while ago.
D.It’s getting better.
